U.S. patent application number 09/747431 was filed with the patent office on 2001-12-13 for hydraulic oil cooler and supplying vessel pressure stabilizer.
Invention is credited to Buysse, John, Story, Rick.
Application Number | 20010050167 09/747431 |
Document ID | / |
Family ID | 26869910 |
Filed Date | 2001-12-13 |
United States Patent
Application |
20010050167 |
Kind Code |
A1 |
Buysse, John ; et
al. |
December 13, 2001 |
Hydraulic oil cooler and supplying vessel pressure stabilizer
Abstract
A fluid delivery system for e.g. a vehicle includes a tank for
holding fluid product, such as propane, a pump for pumping the
fluid product from the tank, the pump being driven by hydraulic
fluid, and a heat exchanger for using the fluid product to cool the
hydraulic fluid. The heat exchanger also causes the fluid product
to increase in temperature. The heated fluid product is returned to
the tank, in the form of a vapor, for example. Embodiments of the
invention provide a number of advantages, including increased pump
flow rates, reduced cavitation and increased pump life, and
elimination of a heat-exchanger fan.
Inventors: |
Buysse, John; (St. Paul,
MN) ; Story, Rick; (Jacksonville, FL) |
Correspondence
Address: |
Wiliam M. Hienz III
Dicke, Billig & Czaja, P.A.
Suite 1250
701 Fourth Avenue South
Minneapolis
MN
55415
US
|
Family ID: |
26869910 |
Appl. No.: |
09/747431 |
Filed: |
December 22, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60174138 |
Dec 31, 1999 |
|
|
|
Current U.S.
Class: |
165/279 ;
165/202; 165/42 |
Current CPC
Class: |
B60P 3/2245 20130101;
Y10T 137/6579 20150401; G05D 27/02 20130101; Y10T 137/4874
20150401 |
Class at
Publication: |
165/279 ; 165/42;
165/202 |
International
Class: |
B60H 003/00; B61D
027/00; B60H 001/00; G05D 015/00; G05D 016/00; G05D 023/00 |
Claims
What is claimed is:
1. A fluid handling system, comprising: a supplying vessel for
holding a first fluid; a discharge flow path in fluid communication
with the supplying vessel, the discharge flow path being disposed
to receive the first fluid from the supplying vessel for discharge
from the supplying vessel; a return flow path in fluid
communication with the discharge flow path and with the supplying
vessel, the return flow path being disposed to receive first fluid
from the discharge flow path for return to the supplying vessel; a
heat-exchange flow path, the heat-exchange flow path being disposed
to contain a second fluid that is free of fluid communication with
the first fluid; and a heat exchanger in fluid communication with
the return flow path and the heat-exchange flow path, the heat
exchanger being constructed and disposed to receive first fluid
from the return flow path and second fluid from the heat-exchange
flow path to cause thermal transfer between the first fluid and the
second fluid.
2. The fluid handling system of claim 1, wherein the second fluid
is hydraulic fluid routed to actuate at least one hydraulic
mechanism, the heat exchanger cooling the hydraulic fluid such that
the hydraulic fluid is maintained at a safe operating temperature
without the use of a cooling fan.
3. The fluid handling system of claim 1, further comprising a
pumping mechanism in fluid communication with the discharge flow
path, the pumping mechanism being constructed and disposed to move
the first fluid along the discharge flow path.
4. The fluid handling system of claim 3, wherein the pumping
mechanism is constructed and disposed to move the first fluid along
the discharge flow path for discharge from the fluid handling
system.
5. The fluid handling system of claim 3, wherein the return flow
path intersects the discharge flow path at an intersection point
downstream from the pumping mechanism.
6. The fluid handling system of claim 5, wherein the first fluid in
the discharge flow path is in the form of a liquid at the
intersection point; further wherein the first fluid in the return
flow path is in the form of a liquid at the intersection point.
7. The fluid handling system of claim 3, wherein the pumping
mechanism is in fluid communication with the heat-exchange flow
path.
8. The fluid handling system of claim 7, wherein the pumping
mechanism is actuated by the second fluid to drive the first fluid
along the discharge flow path.
9. The fluid handling system of claim 1, wherein the heat-exchange
flow path is in fluid communication with a hydraulic mechanism such
that the hydraulic mechanism is actuated by the second fluid.
10. The fluid handling system of claim 9, wherein the hydraulic
mechanism is constructed and disposed to cause the first fluid to
move along the discharge flow path.
11. The fluid handling system of claim 1 wherein the heat exchanger
causes the first fluid to change state between a liquid and a
vapor.
12. The fluid handling system of claim 11, wherein the supplying
vessel contains a liquid space and a vapor space, further wherein
the return flow path returns the first fluid to the vapor space of
the supplying vessel.
13. The fluid handling system of claim 1, wherein the heat
exchanger is a liquid-to-liquid heat exchanger.
14. The fluid handling system of claim 1, wherein the heat
exchanger is constructed and disposed to cause a temperature change
in the second fluid.
15. The fluid handling system of claim 1, wherein the temperature
of the first fluid is less than the maximum desired temperature of
the second fluid.
16. The fluid handling system of claim 1, further comprising: a
temperature sensor in communication with the heat-exchange flow
path for sensing the temperature of the second fluid; and a heat
generator in communication with the heat-exchange flow path, the
heat generator being constructed and disposed for heating the
second fluid in response to an indication from the temperature
sensor.
17. The fluid handling system of claim 1, further comprising: a
pressure sensor constructed and disposed to indicate vapor pressure
in the supplying vessel; and a temperature regulator in
communication with the heat-exchange flow path, the temperature
regulator being constructed and disposed for causing the
temperature of the second fluid to change in response to an
indication from the pressure sensor.
18. The fluid handling system of claim 17, wherein the pressure
sensor and temperature regulator are disposed as an integral unit
in fluid communication with both the return flow path and the
heat-exchange flow path.
19. The fluid handling system of claim 1, further comprising: a
pressure sensor constructed and disposed to indicate vapor pressure
in the supplying vessel; and a flow regulator in fluid
communication with the return flow path, the flow regulator being
constructed and arranged to decrease flow of the first fluid in the
return flow path in response to a high-pressure indication from the
pressure sensor.
20. The fluid handling system of claim 19, wherein the pressure
sensor and flow regulator are disposed as an integral unit in fluid
communication with the return flow path.
21. The fluid handling system of claim 20, wherein the fluid
handling system is disposed on a vehicle comprising an engine;
further wherein the second fluid comprises engine coolant.
22. The fluid handling system of claim 1, wherein the fluid
handling system is disposed on a vehicle comprising an engine;
further wherein the second fluid comprises engine coolant.
23. The fluid handling system of claim 11, wherein the supplying
vessel contains a liquid space and a vapor space, further wherein
the return flow path returns the first fluid to the liquid space of
the supplying vessel.
24. A fluid handling system, comprising: a supplying vessel for
holding a first fluid; first means, in fluid communication with the
supplying vessel, for receiving the first fluid from the supplying
vessel for discharge from the supplying vessel; second means, in
fluid communication with the first means and with the supplying
vessel, for receiving first fluid from the first means for return
to the supplying vessel; third means for containing a second fluid
that is free of fluid communication with the first fluid; and
fourth means, in fluid communication with the second means and the
third means, for receiving first fluid from the second means and
second fluid from the third means to cause thermal transfer between
the first fluid and the second fluid.
25. A fluid handling method, comprising: holding a first fluid in a
supplying vessel; discharging the first fluid from the supplying
vessel into a discharge flow path, the discharge flow path being in
fluid communication with the supplying vessel; receiving first
fluid from the discharge flow path into a return flow path, the
return flow path being in fluid communication with the discharge
flow path and with the supplying vessel; returning first fluid to
the supplying vessel with the return flow path; containing a second
fluid in a heat-exchange flow path, the second fluid being free of
fluid communication with the first fluid; and causing thermal
transfer between the first fluid and the second fluid with a heat
exchanger in fluid communication with the return flow path and the
heat-exchange flow path, the heat exchanger being constructed and
disposed to receive first fluid from the return flow path and
second fluid from the heat-exchange flow path.
26. A vehicle for delivering a fluid product, the vehicle
comprising: a tank adapted to hold the fluid product; a pump
adapted to pump the fluid product from the tank, the pump being
driven by hydraulic fluid; and a heat exchanger adapted to cool the
hydraulic fluid with the fluid product.
27. The vehicle of claim 26, wherein the fluid product is
propane.
28. The vehicle of claim 26, wherein the heat exchanger is adapted
to heat the propane and cause the propane to vaporize, the
vaporized propane being pumped back into the tank.
29. The vehicle of claim 26, wherein the heat exchanger is adapted
to heat the fluid product, further wherein the heated fluid product
is returned to the tank.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The subject matter of this application is related to the
subject matter of U.S. provisional patent application No.
60/174,138, filed Dec. 31, 1999, priority to which is claimed under
35 U.S.C. 119(e) and which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the invention relate to improvements in
pumping fluids from tanks or other supplying vessels. Specific
aspects of the invention, for example, relate to pumping propane
from a vehicle, such as a bobtail or tank truck, with improvements
in e.g. thermal characteristics and pump operation. Other examples
will be described as well.
[0004] 2. Description of Related Art
[0005] Liquefied compressed gases such as propane are generally
transported via truck primarily in two different ways. The first
way is via a transport. A transport is a trailer that holds
approximately 7,000-10,000 gallons of liquid propane. The transport
is used to fill outlying storage tanks and large industrial tanks.
The second way is via a straight truck, which the propane industry
typically calls a bobtail. The bobtail typically holds less than
3,500 gallons of liquid propane and is used to fill residential and
small business propane tanks.
[0006] When a transport unloads, the operator generally will
connect two hoses between the transport and the storage tank. The
first hose connected is called the vapor hose and the second is
called the discharge hose. The purpose for the vapor hose is to
allow the vapor pressures between the transport and the storage
tank to equalize and to allow vapor pressure to be pushed back into
the transport vapor space while they are pumping. This equalizes
the pressures and allows the liquid product pump to pump at a
higher rate and lower pressures, which minimizes noise and internal
damage to the propane pump.
[0007] When a bobtail unloads, the operator typically uses only a
discharge hose. Most bobtails do not have a second vapor hose. Not
having the vapor hose causes two things to happen. First, as the
propane pump on the bobtail pumps liquid propane from the bobtail
into the storage tank, the pressure in the storage tank continues
to rise and causes back pressure on the discharge line. This back
pressure causes the discharge line pressure to continue to rise,
causing the pump to work harder and thus reducing the flow rate and
increasing the wear of the propane pump. Second, as the propane
pump pulls product out of the bobtail tank it creates a vacuum
inside the bobtail tank. This vacuum creates bubbles in the propane
which are then pulled through the propane pump. As these bubbles
are pulled through the propane pump they compress and then expand
rapidly, potentially causing damage to the internal vanes and rotor
of the propane pump. These bubbles reduce the flow rate of the pump
and create a higher level of pump noise.
[0008] Liquid products that do not change state as readily, such as
fuel oil and refined fuel, are transported via truck primarily in
two different ways. The first way is via a transport, described
earlier. The second way is via a straight truck. The straight truck
carries 500-5,000 gallons of product. The straight truck typically
delivers to residential customers and to small industrial
customers.
[0009] With liquid products that do not change state, both the
transport and the straight truck unload in approximately the same
way. The operator connects a single discharge hose between the
transport or straight truck to the storage tank. Once this has been
accomplished, the operator then starts the pump and pumps the
liquid product into the storage tank. Since this type of liquid is
not pressurized to maintain it as a liquid, the transport, straight
truck and storage tanks can all be vented to atmosphere. This
eliminates the need for a vapor hose.
[0010] Thus, the propane bobtail delivery market and the fuel-oil
and refined-fuels tank-truck delivery market, for example, are
similar in that typically they both use a tandem-axle-style truck
with a multi-thousand gallon tank mounted on the chassis. These
vehicles are used to deliver typically small quantities of e.g.
propane, fuel oil, diesel fuel and gasoline to e.g. homes, farms
and small businesses.
[0011] Currently, there is a movement in these industries to change
from driveline-driven product pumps to hydraulic drives. This
change is coming from a number of areas, e.g. safety, maintenance
and a need to either mount the product pump in a location that
cannot be easily driven by a driveshaft or a need for two or more
product pumps on a truck. The tank-truck market is shifting towards
having larger and multicompartment tanks on their trucks. This
shift allows more efficient use of their trucks and their
employees.
[0012] It would be desirable to take advantage of the movement to
change from driveline-driven product pumps to hydraulic drives, to
further capitalize on the attendant advantages. Additionally, a
need exists to diminish the problems of back pressure and
vacuum-induced bubbles in e.g. propane, which bubbles are then
pulled through the propane pump. It would also be desirable to
diminish the disadvantages caused by using a fan for cooling, e.g.
noise, vibration/resonance, and maintenance/upkeep concerns.
SUMMARY OF THE INVENTION
[0013] To achieve the above and other goals, one embodiment of the
invention uses the product that the customer is pumping, e.g.
propane, to cool the hydraulic oil used to run the pump. A
liquid-to-liquid heat exchanger receives the hydraulic oil line and
a line containing the pumped product. Approximately two gpm of
product can be pumped through the heat exchanger, according to one
embodiment. The two liquids are separated by thin channels of e.g.
stainless steel or another material. The heat exchanger cools the
hydraulic oil and warms the customer's liquid product. Embodiments
of the invention have particular advantages in e.g. the propane
industry. Propane is heated, vaporized and then pumped back into
the top of the supplying tank. This vaporized propane increases
pump flow rates, reduces cavitation and increases pump life. These
advantages are obtained, according to embodiments of the invention,
with no fan motor, better product pump performance, longer product
pump life, and smaller and lighter pump weights.
[0014] The theory behind embodiments of the invention is twofold
for e.g. propane types of application. First, by using the liquid
propane as the cooling agent inside the liquid-to-liquid heat
exchanger, the hydraulic oil is kept at a safe operating
temperature without the use of a cooling fan. Second, as the
hydraulic oil passes through the heat exchanger it heats the liquid
propane.
[0015] The heated liquid propane is boiled or vaporized and then
pumped back into the vapor space, or liquid space, in the bobtail
tank. By reintroducing this vapor back into the bobtail tank, the
problems that were stated above are minimized. Embodiments of the
invention decrease the length of time during which product can be
unloaded, stabilize the vapor pressure in the bobtail tank, reduce
pump wear and noise, and cool the hydraulic system without the need
for any type of cooling fan.
[0016] Embodiments of the invention for liquid products that do not
as readily change state regulate a small amount of the liquid
product being pumped through the heat exchanger. As the liquid
passes through the heat exchanger, it cools the hydraulic oil. The
heated liquid product is the reintroduced back into e.g. either the
transport or straight truck tank or back into the discharge line of
the pump.
[0017] Embodiments of the invention provide significant advantages,
in that they can cool the hydraulic oil without the need for a
cooling fan and can aid in the pumping of liquids that become more
difficult to pump in colder climates.
[0018] Embodiments of the invention can be described as a
combination of a hydraulic oil cooler and a supplying vessel
pressure stabilizer. Embodiments of the invention can be used in
applications that require hydraulic oil to be cooled while it is
operating a product pump that is pumping some type of liquid
product. The hydraulic oil is cooled via a "liquid-to-liquid" heat
exchanger, for example. This heat exchanger can have up to at least
three channels allowing up to at least three different liquids to
pass through it at any one time.
[0019] On one side of the heat exchanger is the hydraulic oil and
on the other side(s) are one or more liquid products that are being
pumped by the product pump(s). The liquid products absorb the heat
of the hydraulic oil. In effect, embodiments of the invention are
cooling the hydraulic oil and heating the amount of liquid product
that is being pumped through the heat exchanger. This device will
work when the temperature of the liquid product being pumped is
less than the maximum desired hydraulic oil temperature. Different
types of liquids at different flow rates affect the cooling
capacity of the heat exchanger and the amount of heat being
transferred into the liquid product being pumped. Hydraulic oil
flow rates at varying pressures affect the amount of heat (BTU's)
that are produced.
[0020] At least two different types of liquid products can be used
with this device. The first is a "non-state-changing" liquid, as
referenced above. This type of liquid does not change its state
when the amount of heat (BTU's) that a hydraulic system creates is
dissipated and absorbed by the liquid. For example, embodiments of
the invention simply add a fixed amount of BTU's to diesel fuel.
These added BTU's increase the temperature of the diesel fuel to a
predetermined and controlled safe temperature. The second type of
liquid, the "state-changing" liquid, begins to boil or vaporize as
its temperature is changed. These types of liquids are typically
referred to as liquefied compressed gases. For example, propane
will boil or vaporize as heat is introduced to it.
[0021] According to embodiments of the invention, the liquid
product being pumped through the heat exchanger is reintroduced
back into the supplying vessel once it has circulated through the
heat exchanger. Depending upon the product, it will enter back into
the supplying vessel as a warmed-up liquid or as a boiling liquid
or vapor. This vapor can be extremely beneficial to certain types
of supplying vessels to aid in the pumping process. This benefit
will be described in detail, further into this description.
[0022] Embodiments of the invention contain a "liquid-to-liquid"
heat exchanger, a hydraulic reservoir, and a hydraulic oil filter.
These parts are manufactured and assembled into a package that is
compact, light-weight and easy to install for the customer.
Embodiments of the invention also diminish many of the problems
referenced above, e.g. back pressure, vacuum-induced bubbles,
cavitation, noise, vibration/resonance, maintenance/upkeep
concerns, and the like.
[0023] Additional features and advantages according to embodiments
of the invention will become apparent from the remainder of this
patent application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Embodiments of the invention will be described with respect
to the figures, in which like reference numerals denote like
elements, and in which:
[0025] FIG. 1 is a schematic view of a cooler/stabilizer according
to an embodiment of the invention;
[0026] FIG. 2 is a schematic view of a cooler/stabilizer having a
temperature-sensing, heat-generating control block according to an
embodiment of the invention;
[0027] FIG. 3 is a detailed view of the temperature-sensing,
heat-generating control block of FIG. 2;
[0028] FIG. 4 is a schematic view of a cooler/stabilizer having a
pressure-sensing, heat-generating control block according to an
embodiment of the invention;
[0029] FIG. 5 is a detailed view of the pressure-sensing,
heat-generating control block of FIG. 4;
[0030] FIG. 6 is a schematic view of a cooler/stabilizer having a
pressure-sensing, shut-off valve control block according to an
embodiment of the invention;
[0031] FIG. 7 is a detailed view of the pressure-sensing, shut-off
valve control block of FIG. 6; and
[0032] FIG. 8 is a schematic view showing a cooler/stabilizer
according to an embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] Turning first to FIG. 1, fluid handling system 10 according
to an embodiment of the invention includes supplying vessel or tank
15 for holding first fluid 20, e.g. propane, fuel oil, diesel fuel,
gasoline, or other liquid. Both liquefied compressed gases and
liquid products that do not change state as readily are
contemplated for use as first fluid 20. Supplying vessel 15 also
defines vapor space 25 disposed above first fluid 20.
[0034] Discharge flow path 30 is in fluid communication with
supplying vessel 15. Discharge flow path 30 is disposed to receive
first fluid 20 from supplying vessel 15 for discharge from
supplying vessel 15 and, according to embodiments of the invention,
from fluid handling system 10 to e.g. receiving tanks or the like
at homes, farms, small business, etc. According to embodiments of
the invention, discharge flow path 30 is defined, at least in part,
by suction inlet port or pump inlet port 35, product pump 40 and
pump outlet discharge line 45. Product pump 40 is a pumping
mechanism that is constructed and disposed to move first fluid 20
along discharge flow path 30.
[0035] Return flow path 50 is in fluid communication with discharge
flow path 30 and, ultimately, with supplying vessel 15. Return flow
path 50 is disposed to receive first fluid 20 from discharge flow
path 30 for return to supplying vessel 15. According to the
illustrated embodiment, return flow path 50 is defined, at least in
part, by product/coolant line 55, which intersects pump discharge
line 45 at intersection point 60, heat exchanger 65, and
liquid/vapor return line 70. Product/coolant line 55 is connected
to heat exchanger 65 via flow control 63.
[0036] Fluid handling system 10 also comprises heat-exchange flow
path 75, which is disposed to contain second fluid 78, which is
e.g. hydraulic fluid or oil for actuating pump 40. Second fluid 78
is free of fluid communication with first fluid 20, according to
embodiments of the invention.
[0037] According to the illustrated embodiment, heat-exchange flow
path 75 is defined, at least in part, by hydraulic return line 80,
which is connected via hydraulic filter 85 to hydraulic tank
assembly 90. Hydraulic tank assembly 90 includes hydraulic breather
95 and site/level oil gauge 100, according to the illustrated
embodiment. Hydraulic suction line 105 connects hydraulic tank
assembly 90 to hydraulic pump 110, which is connected to power
take-off (PTO) 115. Hydraulic pressure lines 120 and hydraulic flow
and PSI block 125 connect hydraulic pump 110 to deliver second
fluid 78 for actuating product pump 40 via hydraulic motor 130,
which is mounted by hydraulic motor mounting assembly 135. Thus,
pump 40 is in fluid communication with heat-exchange flow path
75.
[0038] Case drain line 138 connects hydraulic tank assembly 90 to
hydraulic motor 130.
[0039] In operation, pump 40 is activated to move first fluid 20
along discharge flow path 30 for discharge from supplying vessel 15
and/or fluid handling system 10. First fluid 20 in discharge flow
path 30 is in the form of a liquid at intersection point 60
according to embodiments of the invention, as is first fluid 20 in
return flow path 50 at point 60.
[0040] The temperature of first fluid 20 in return flow path 50 is
cooler upon entering heat exchanger 65 than second fluid 78 in
heat-exchange flow path 75. In heat exchanger 65, thermal transfer
occurs between first fluid 20 and second fluid 78. According to one
embodiment, second fluid 78, e.g. hydraulic oil, is cooled by first
fluid 20, e.g. propane, and first fluid 20 is heated by second
fluid 78. Thus, heat exchanger 65 is constructed and disposed to
cause a temperature change in both first fluid 20 and second fluid
78, and the temperature of first fluid 20 is generally less than
the maximum desired temperature of second fluid 78.
[0041] In summary, fluid handling system 10, which can be disposed
on a vehicle, such as a truck, comprises tank 15 for holding fluid
product 20, pump 40 for pumping fluid product 20 from tank 15, pump
40 being driven by hydraulic fluid 78, and heat exchanger 65 for
using fluid product 20 to cool hydraulic fluid 78. Fluid product 20
can be propane. Further, heat exchanger 65 heats propane or other
first fluid 20 and causes it to vaporize. The vaporized propane in
liquid/vapor return line 70 than is pumped and returned either to
vapor space 25 or the liquid space of tank 15. In other words, heat
exchanger 65 heats fluid product 20 and returns it to tank 15.
[0042] Three control blocks can be offered as options to the FIG. 1
embodiment, as will now be described with respect to FIGS. 2-7.
[0043] The first of the three control blocks is
temperature-sensing, heat-generating block 140, shown generally in
FIG. 2 and in detail in FIG. 3. Block 140 is disposed in
heat-exchange flow path 75, just before heat exchanger 65, in the
illustrated embodiment. Block 140 includes valve body 145,
temperature sensing cartridge 150, heat-generating cartridge 155,
hydraulic oil inlet and outlet ports 160, 165, hydraulic oil
pressure port 168, and hydraulic oil pressure gauge 170. Block 140
senses the temperature of the hydraulic oil or other second fluid
78 by temperature sensing cartridge valve 150. It then will
internally either route the e.g. hydraulic oil over hydraulic heat
generating cartridge valve 155 and then into heat exchanger 65, or
it will route the hydraulic oil directly to heat exchanger 65,
bypassing hydraulic heat-generating cartridge valve 155. The
temperature at which block 140 switches the routing from one to the
other can be changed to meet the requirements for a particular
environment or application.
[0044] Thus, temperature sensor 150 is in communication with
heat-exchange flow path 75 for sensing the temperature of second
fluid 78. Heat generator 155 is also in communication with
heat-exchange flow path 75, and is constructed and disposed for
heating second fluid 78 in response to an indication from
temperature sensor 150.
[0045] Block 140 presents significant advantages. A cold outside
air temperature or other ambient environment produces a colder tank
and therefore less vapor pressure within the tank. In other words,
the fluid product within the tank is more condensed. This cooler
temperature causes pump 40 to draw a vacuum within tank 15 more
quickly, potentially starting cavitation in pump 40 at an earlier
time. Heating second fluid 78 causes increased thermal transfer to
first fluid 20, increasing the reduced vapor pressure in tank 15
and tending to diminish the cavitation problem. Additionally,
heated fluid 78 provides e.g. start-up advantages in fluid handling
system 10.
[0046] The second unique, optional control block for fluid handling
system 10 is pressure-sensing, heat-generating control block 175,
shown in FIG. 4 in heat-exchange flow path 75 and shown in more
detail in FIG. 5. Block 175 senses vapor pressure in supplying
vessel 15 via sensing line 180 routed between vessel 15 and control
block 175. Via product sensing port 185 and end cap 187, which
includes a filter, the vapor pressure in supplying vessel 15 pushes
on piston 190. Piston 190, in turn, moves against bias spring 195
disposed within piston chamber 200. This movement determines a
pass-through orifice size, by moving orifice spool 205, anchored in
spool block 210. Hydraulic oil or other second fluid 78 enters
block 175 at inlet port 215, passes through the orifice whose size
is determined in the manner described above, and then out through
outlet port 220 enroute to heat exchanger 65. The size of the
orifice determines the amount of hydraulic heat transferred in heat
exchanger 65. The lower the product vapor pressure, the smaller the
orifice size, which in turn equals a higher hydraulic oil
temperature. The maximum pressure limitations of supplying vessel
15 will determine the maximum amount of hydraulic heat that can be
generated through control block 175. Thus, control block 175
includes a pressure sensor constructed and disposed to indicate
vapor pressure in supplying vessel 15, and a temperature regulator
in communication with heat-exchange flow path 75, the heat
generator being constructed and disposed for heating second fluid
78 in response to an indication from the pressure sensor. According
to one embodiment, the pressure sensor and temperature regulator
are disposed as an integral unit 175 in fluid communication with
both return flow path 50 (via sensing line 180) and heat-exchange
flow path 75.
[0047] The third unique, optional control block is
pressure-sensing, shut-off control block 260, illustrated in FIG. 6
in return flow path 50 and illustrated in more detail in FIG. 7.
Block 260 is designed to mechanically shut off the flow of cooling
liquid (e.g. first fluid) 20 if and when the pressure in supplying
vessel 15 reaches a predetermined pressure. This shut-off protects
supplying vessel 15 form over-pressurization.
[0048] Block 260 senses vapor pressure in supplying vessel 15 via
sensing line 265, which is in fluid communication with return flow
path 50 and thus is in fluid communication with supplying vessel
15. The vapor pressure in supplying vessel 15 pushes against piston
290, via product sensing port 285 and end cap 287 (which includes a
filter). Piston 290 in turn moves against bias spring 295 disposed
within piston chamber 300. This movement determines whether or not
spool 305 moves within spool block 310 to a position that does or
does not allow first fluid 20 (product/coolant) to flow from inlet
port 315 to outlet port 320 and on to heat exchanger 65. Thus,
according to this embodiment, fluid handling system 10 includes a
pressure sensor constructed and disposed to indicate vapor pressure
in supplying vessel 15, and a flow regulator in fluid communication
with return flow path 50, the flow regulator being constructed and
arranged to decrease flow of first fluid 20 in return flow path 50
in response to a high-pressure indication from the pressure sensor.
The pressure sensor and flow regulator are disposed as an integral
unit 260 in fluid communication with return flow path 50.
[0049] Returning to FIG. 6, according to this embodiment heat
exchanger 65 is in fluid communication with engine 330 via engine
coolant return lines 335, 340. Engine coolant bypass valve 345,
preferably a ball valve, allows bypass of heat exchanger 65 via
engine coolant bypass line 348 if desired. Power take-off 350 draws
power off engine 330 for activating pump 40 via driveline 355.
Thus, fluid handling system 10 according to this embodiment uses
engine coolant as an equivalent to the previously described second
fluid 78. Alternatively, hydraulic oil or other fluids can also be
used in this embodiment in the manner described previously.
[0050] FIG. 8 shows additional aspects of fluid handling system 10,
including system casing 360, fittings 365 for connection with pump
110, and fittings 370 for connection with hydraulic motor 135 and
pump 40. Pump 110, according to this embodiment, can have a pump
speed of 1,500 rpm, producing 16 gpm at 1,500 PSI. PTO 115 can
accommodate 1,300 engine rpm, according to one embodiment.
Hydraulic motor 135 optionally can be attached to pump 40 by
hydraulic adapter 375, and pump 40, according to one embodiment, is
a 10 HP pump at 640 rpm. Of course, other sizes, speeds and related
parameters are contemplated according to embodiments of the
invention.
[0051] While embodiments of the invention have been described with
reference to particular preferred embodiments, the invention is not
limited to the specific examples given. Use with a wide variety of
tractors, trailers, and other vehicles and devices and with a wide
variety of liquids is contemplated. Various materials can be used
according to the invention, e.g. stainless-steel componentry, or
any material having strength and durability sufficient to withstand
severe operational conditions. Various modifications and changes
will occur to those of ordinary skill upon reading this disclosure,
and other embodiments and modifications can be made by those
skilled in the art without departing from the spirit and scope of
the invention.
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